Solid phase synthesis is commonly used to produce polymers such as peptides, polynucleotides and polysaccharides. This method of synthesis employs a technique whereby individual amino acids, mononucleotides or monosaccharides are sequentially added to a growing chain that is covalently linked to an insoluble solid support. Specifically, peptides can be produced by attaching either the amino or carboxyl group of a protected or derivatized amino acid to the solid support. The next amino acid in the desired sequence is then added under conditions suitable for forming an amide linkage. Again, the complementary amino or carboxyl group is protected prior to the addition. The protecting group is then removed from the newly added amino acid residue and the next protected amino acid added. After all the desired amino acids have been linked in the proper sequence, any remaining protecting groups are removed and the peptide cleaved from the solid support. Polynucleotides and polysaccharides can be similarly produced by the sequential addition of selectively blocked monomer units to a growing chain immobilized on the solid support.
The method is tedious and time consuming, requiring the addition of several reactants and washes. Thus, when more than one peptide is desired, the process can require days or even months.
U.S. Pat. Nos. 3,531,258 3,557,077, 3,647,390, 4,353,989, 3,362,699 and 4,668,476 all describe automated devices for solid phase peptide synthesis. Although these devices largely eliminate the need for user interaction, they are complex, costly, and only synthesize one peptide at a time. Thus, if a multiplicity of peptides are desired simultaneously, more than one machine must be used. This is often cost-prohibitive.
U.S. Pat. No. 3,715,190 discloses a manual system for solid-phase peptide synthesis. Although less costly than the automated devices, this system does not allow the simultaneous production of more than one peptide.
Apparatuses such as those disclosed in U.S. Pat. Nos. 4,728,502, 4,671,941, 4,517,338 and 4,483,964 are capable of synthesizing multiple polynucleotides simultaneously. As with those synthesizers described above, these devices are complex, automated and very costly. They also are not easily adapted for solid phase peptide synthesis.
Thus, there is a need for a simple, inexpensive system for synthesizing a multiplicity of peptides and other polymers simultaneously.